In computer and telecommunications networks, presence information is often used as a status indicator that shows whether a user of a device in the network is available for communication. The presence information is normally provided by a presence application in the device, e.g. a client computer, and transmitted to a presence server connected to the network, e.g. the Internet or a local area network, from which it is made available for other devices or computers connected to the network. The presence information may be based on the activity performed in or by the computer of the user. As an example, the presence information may show that the user is available when a keyboard or a mouse is in use. When the keyboard or the mouse has not been used for some time, the presence information may indicate that the user is away.
Often a computer also comprises a soft phone application, which uses a headset system comprising a headset and a base station to perform telephone communications via the network. When a telephone conversation is performed by the soft phone application the presence information could indicate that the user is involved in a conversation.
As examples of commercially available presence systems, or systems using presence information, Microsoft Office Communicator and Cisco Unified Communicator can be mentioned.
In such presence systems the user presence status is thus derived solely from computer and/or soft phone activity. This, means that if the user is busy with other activities, such as speaking on a mobile telephone or a desktop telephone, and thus unavailable for a new communication, the presence information obtained from the presence server regarding this user falsely indicates that the user is available.
It could be possible to install a special presence application on mobile telephones and have this application send information about call activity to the presence server, either via the mobile network or via e.g. a Bluetooth link. However, as mentioned, this solution requires that a special application is installed on mobile telephones, which is not practical, and further, it does not solve the problem for e.g. desktop telephones.
US 2009/305632 shows a system in which a Bluetooth headset connected by a Bluetooth link to a mobile telephone can communicate presence information via a second Bluetooth link to a computer on which a presence application is running. However, this solution requires that the headset is capable of communicating via two Bluetooth links simultaneously and also that the headset comprises circuitry for providing the presence information. Further, like the solution mentioned above, this solution does not solve the problem for e.g. desktop telephones.